Abstract The dynamic response of a compression system is the complex behaviors reacted by compressor subject to non-uniform inflow excitation. However, in real operating condition, would work at wide range altitudes within flight envelope, which forces us consider how Re additionally affects performance loss and characteristic due inlet distortion. To explore this issue, full-annulus unsteady 3D simulation has been used calculate transonic axial fan with 180-deg distortion different Re....

Abstract Over recent years, the aeroelastic problem of fan blades has become significantly serious due to demand for high performance aero-engines. To explore issue flutter, instability is represented by aerodynamic damping. When inlet condition uniform, damping mainly caused temporal factor, and classic flutter usually does not occur usage mistuning. However, with existence circumferentially non-uniform components in distorted inflow, also affected spatial which may alter occurrence...

This study reveals the blockage effects on vortex shedding, lock-in mechanism of a forced oscillating cylinder, and coupling oscillation. The wind tunnel experiments large eddy simulations were conducted at Reynolds number 2000, encompassing range ratios from 0.15 to 0.5. cylinder is subjected harmonic oscillations in direction perpendicular incoming flow investigate frequency mechanism. research findings demonstrate that both vibration significantly influence dynamics shedding by altering...

Partial surge is a type of instability inception in transonic compressors and occurs the form axisymmetric low-frequency disturbances localized hub region. Previous studies illustrate that frequency partial set by Helmholtz entire system, which motivates to propose hypothesis system response performs an important role formation surge. For further verification, series experiments are conducted explore link between propagating feedback this study. In first case, additional test point on wall...

Abstract Boundary-layer ingestion systems have the potential to improve propulsion efficiency using fluid with lower momentum near airframe. However, they also bring variations in velocity and total pressure, leading a complex distortion of flow at inlet stage form circumferential step variation significant strength. Previous simulation NASA Rotor 67 under 120-deg sector revealed occurrence first-order bending mode excited by second engine order (2EO) circumferentially distorted inflow. To...

Active flow control methods are commonly used in expanding the operating range of compressors. Indeed, unsteady active main focus researchers due to their effectiveness. For constructing an system, reliable actuators significant. To compare with conventional such as synthetic jet and rotating valves, fluidic oscillators have structurally robust characteristics can generate self-excited self-sustained oscillating jets, which leads its higher applicability compressors under severe working...

The performance and stability of the transonic fan stage with a nonuniform inflow is key issue in aero engine operation, coupling inlet distortion low Reynolds numbers at high altitude creates more severe challenges to engines. This work used computational methods explore number. To investigate this issue, NASA 67 180° total pressure number was selected as test case. Full-annulus 3D unsteady simulations were conducted reveal details flow field under conditions. results different conditions...

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Abstract This study investigates the biomechanical adaptations of longitudinal arch (LA) in long-distance runners, focusing on changes stiffness, angle, and moment during a 60-minute run. Twenty runners participated this experiment, were asked to run at speed 2.7 m·s-1 for 60 minutes. The kinematic kinetic data collected five-minute intervals running calculated, including stiffness LA loading phase (k load ) unloading unload ), maximum (M max range angle change (∆θ ). Foot morphology was...

Boundary layer ingestion propulsion systems have attracted much attention due to their significant potential reduce the fuel consumption of future commercial aircraft. However, aeroelastic stability fan blade is affected by continuous non-uniform incoming flow induced boundary layer. When blades rotate in junction area between distorted and clean area, pressure fluctuations occur. This phenomenon triggers a dynamic response process blade. Previous numerical investigations explored influence...

For fans of a variable-cycle engine, good aerodynamic performance over wide range rotating speeds is essential. However, when supersonic cascades designed for high upstream Mach number operate under low number, starting problem may occur, which significantly decreases the fan blades. As result, operating severely limited. To solve caused by mismatch between geometry and morphing cascade developed. Thus, this study mainly focuses on effect static deformation driven smart materials...